Determine Solubility of KClO3 Salt.

Authors Avatar

Universiti Tunku Abdul Rahman

UESB 1113 General Laboratory I

Atomic Structures & Periodicity

Bachelor of Science (Hons) Biotechnology

Year 1 Semester 1

Experiment 9:

Determine Solubility of KClO3 Salt.

Name/ID: Hew Xin Hong / 05UEB02306

                       Low Wei Seong / 05UEB02315

Tutorial Group: Group 4

Date: 25th July 2005

Tutor: Mr. Lee Chong Yong

Experiment 9

Title: Determine solubility of KClO3 salt.

Objectives:        

  • To determine the solubility of a given salt, KclO3 at different temperature.
  • State the different between a saturated solution and the original solution.
  • Plot a graph of solubility against temperature to determine the solubility.

Theory and Background:

In this experiment, we will study about solubility of solute in the solution. Solubility is meaning the maximum amount of a substance dissolved in a given volume of solvent. A solution is formed when a solid solute is begin to dissolve in a solvent. The particles of solute collide with the surface of the solid and attached on it. This process is called dissolve. While on the opposite way, is crystallization where particles of solute formed back by proper arrange. The process is affected by some factor that will introduce later. The dissolve and crystallization process is represent as below:

                  dissolve

Solute + solvent   Solution

                                     crystallize                

The factor that influence solubility includes temperature, salinity, pH, dissolved organic matter (DOM), and co-solvents. And in this experiment, we will only using the temperature factor to influence the solubility, other factor will be briefly introduce. Generally, as temperature increase, solubility for solids or salts will increase which is follow the trends. But for solubility of liquids or gases, if temperature increase, the solubility is either increase or decrease depend on the solvent. The influence of temperature on water solubility can be explained by the van’t Hoff equation that stated:

ln Csat = -ΔH/(RT) + Constant

        For salinity influences, as salinity increases, the solubility of neutral organic compounds decreases (activity coefficient increases). For

pH, it increase apparent solubility, its effect depends on the structure of the solute. If the solute is subject to acid/base reactions then pH is vital in determining water solubility. The ionized form has much higher solubility than the neutral form. The apparent solubility is higher because it comprises both the ionized and neutral forms. The existing solubility of the neutral form is not affected. While

DOM increases the apparent water solubility for sparingly soluble (hydrophobic) compounds.  DOM serves as a site where organic compounds can partition, thereby enhancing water solubility.  Solubility in water in the presence of DOM is explained by the equation below:

 

Csat,DOM = Csat (1 + [DOM]KDOM)

[DOM] = concentration of DOM in water, kg/L

KDOM = DOM/water partition coefficient.

And for co-solvent factor, its presence increases the solubility of hydrophobic organic chemicals. It can completely change the solvation properties of “water”.

A solution is unsaturated when solute keep dissolving if more solute is added to the liquid. A solution is saturated when the liquid has dissolved all of the solute that is possible.  Additional solute will not further dissolve if added to a saturated solution. Supersaturated solution is a solution when there is a suitable condition sometimes possible to form a solution that contain greater amount of solute than that needed to form a saturated solution. Supersaturated solutions are unstable. When prepare for crystallization, the molecules or ions of solute must arrange themselves properly to form crystals.

Join now!

The unit we been use for solubility in this experiment is gram/100-mL. There are many kinds of units to describe how much solute we have in a solvent. There are some examples of other unit that describes solubility. That is g/mol, g/litre, mol/litre, mass percent, mass per volume, and parts per million.

Below the table displays the solubility of some common substances in g/100 mL at the specified temperature.

                

Solubility process is a process of solubilization for organic solute in water in a mechanistic perspective. First, it involves ...

This is a preview of the whole essay